need to solve the following questions, I do not have to them now, take your time, but I need to solve all the questions, thank you

((((questions ask law)))))

21. In case of invalid contract, it is declared so: * (2 Points) From the moment the contract was concluded From the moment it produced legal effects From the moment it is discovered that the contract is void From the moment the object or cause of the contract was found illegal 20. contract responsibility is based on: * (2 Points) Wrongdoing Contract Damages Non of the above 21. In case of invalid contract, it is declared so: * (2 points) From the moment the contract was concluded From the moment it produced legal effects From the moment it is discovered that the contract is void 10. Which of the following statements is correct? (2 Points) The theory of obligation changes from time to time The theory of obligation changes every 2 years The theory of obligation changes for a long period of time The theory of obligation is more static which means its does not change for a long time 11. If one party does not perform the contract, the other party to the contract may hold the first party in breach of the contract and can ask for: (2 Points) None of the above damages specific performance and/or compensation compensation 20. If one party does not perform the contract, the other party to the contract may hold the first party in breach of the contract and can ask for: (2 Points) compensation specific performance and/or compensation damages None of the above